Cable sheathing tool



Oct. 24, 1961 H. c. SLECHTA CABLE SHEATHING TOOL Filed Nov. 2, 1955 l/VVf/VTOR H C. SLECHTA A T TORNEY 3,005,480 CABLE SHEATHING TOOL Henry C. Slechta, Plainfield, N.J., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed Nov. 2, 1955, Ser. No. 544,414 2 Claims. (Cl. 153-1) cable sizes to add suflicient flexibility to the cable and prevent cracking of the sheath during bending. Flat or uncorrugated strips may be formed about small cable cores and provide suitable flexibility but special care must be taken in forming the flat strip about the cable core to i ite States Patent prevent stretching or buckling portions of the flat strip.

The present object of the invention is a tool which, though simple in structure, is highly eflicient in forming fiat metallic strips on cable cores.

In one embodiment of the invention, according to the object, the tool includes a forming element having a flat entrance end, a substantially cylindrical exit end concentric with the path of the cable and intermediate lateral portions curving from the flat entrance end to the cylindrical exit end to form a flat metallic strip about the cable core. In the present instance, the element is bent longitudinally to cause all portions of the metallic stn'p throughout its width to travel substantially like distances.

More specifically, the apparatus includes an initially straight bar disposed longitudinally of the forming element and welded to the central portion thereof. A part of the tool includes a guide for the cable core which is substantially semi-circular in cross-section, has its longitudinal central portion welded to an initially straight bar, the two bars being fixed to legs of U-shaped brackets to produce a substantially integral unit of the bars, the forming element and the cable guide. This unit is bent longitudinally, assisted by lateral notches cut in the element and the cable guide whereby a flat metallic strip advanced longitudinally with the cable core through the tool will be caused to move in a path directing all longitudinal lines or portions of the strip like distances, while the strip is formed about the cable core, to equalize the stress transversely of the strip and thereby eliminate stretching and buckling of any portions of the strip while the strip is uniformly formed on the cable core.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawing, wherein:

FIG. 1 is a side elevational view of the tool;

FIG. 2 is a top plan view of the tool;

FIG. 3 is an end elevational view taken substantially along the line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken substantially along the line 44 of FIG. 2;

FIG. 5 is a sectional view taken along the line 5--5 of FIG. 2 (not including the cable core or the metallic strip); and

FIG. 6 is a sectional view of the sheathed core taken near the exit end along the line 6-6 of FIG. 2.

The tool in the present instance is employed in a cable forming line wherein certain materials are applied to or formed on a cable core 10 as it is advanced longitudinally in a conventional manner through a series of stations one of which includes the present tool. At this station a flat strip 11 of metal such as aluminum is to be formed about the core.

fixed thereto.

3,005,480 Patented Oct; 24, 1961 The tool includes two main elements which are aforming element 12 and a cable core guide 14. The element 12 has a fiat entrance end 15 provided with an arcuate guide 16 including side members 17 and a cross-bar 18 An exit end 20 of the element 12 is substantially cylindrical in cross-section as illustrated in FIG. 5 while the intermediate portions, that is, those portions between the fiat entrance end 15 and the cylindrical exit end 20 are curved as illustrated in FIGS. 1 and 2 to form the flat metallic strip 11 about the cable core. The element 12 has a plurality of slots 21 cut at spaced positions therein and extending laterally, short of a central portion 22 thereof, and through the side edges thereof. the central portion 22 of the element 12 is straight and is spot welded at spaced portions throughout its length to an initially straight bar 24.

- Initially, the cable guide 14 is straight other than the belled or outwardly flared mouth 25 thereof. The guide 14 has slots 26 cut at spaced positions therein and extending laterally from a central portion 27 thereof through the side edges. The guide 14 is spot welded at spaced positions to an initially straight'bar'29 along the central porthe cable core guide 14 respectively. After this forming operation has been performed, a bracket 35 is fixed to the bar 24 by suitable means such as welding and it is mounted through the aid of bolts 36 in slots 37 on a suitable support or frame 38, which may be a part of an adjacent apparatus, or an individual support for the tool.

Considering now the function of the tool let it be assumed that the cable core 10 is threaded through the tool with the leading end of the metallic strip and the cable core connected to an advancing means (not shown) in a conventional manner and advanced at a prtdetermined speed longitudinally. During longitudinal advancement of the cable core and the metallic strip, the cable core is caused to move through the arc or curved path controlled by the guide 14 to force the cable core and the metallic strip into close engagement with the forming element 12. As a result, the flat metallic strip 11, as it passes beyond the fiat entrance end 15 of the forming element, will be caused to bend longitudinally about the cable core and initially about the guide 14 as illustrated more clearly in FIGS. 1 and 2. After the cable core leaves the guide 14, the element 12 will function to continue guiding the cable core and metal strip in the desired path while forming the initially flat metallic stn'p about the core before it leaves the element through the exit end 20.

In view of the edges of the strip being arcuately formed and consequently travel-ling a distance greater than that along the constant mid-portions of the strip, the provision of the longitudinal curvature of bars 24 and 29 on element 12 and guide 14 respectively enables the mid-portion of the strip to travel a distance equal to that of the outer edges of the strip. Thus as the metal strip travels in the longitudinally curved path all longitudinal portions of the metallic strip throughout its width will be caused to travel like distances to equalize the stress transversely of the strip to make possible the formation of a fiat metallic strip on a cable core free of buckling or other disturbances to the metallic strip.

It is to be understood that the above described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrange- Initially.

ments may be :readily devised by those skilled in the art which will embody the principles of the invention and fall Within the spirit and scope thereof.

What is claimed is:

1. A tool for use in forming a metallic stripvon a cable core advanced longitudinally in a given path comprising a forming element having a flat entrance end for receiving the strip, a substantially cylindrical exit end concentric with the exit path and intermediate lateral portions curving from the flat entrance end to the cylindrical exit end to form a trough-like structure open from the entrance end for over half the length of the forming element, the .forming element being bent arcuately longitudinally to produce a-concave contour in the trough-like structure of the forming element, a trough-like guide inverted in the open portion of the trough-like structure of the forming element and bent arcuately longitudinally to produce a convex contour parallel with the concave contour of the forming element to guide the cable core and cause the cable core to exert a force against the central part of the metallic strip advancing through the forming element to cause it to travel in the laterally and longitudinally curved path provided by the forming element, the length of the curved path followed by the central part of the strip being substantially equal to the length of the spiral paths followed by the edges thereby minimizing stretching thereof, arcuately curved elongated reinforcing bars fixed respectively to outer surfaces of the forming element and the guide to maintain the arcuate curvature thereof, and U-shaped brackets having like legs thereof fixed respectively to the bars to maintain the relative parallel spaced positions of the forming element and the guide.

2. A tool for use in forming a metallic strip on a cable .core advanced longitudinally in a given path comprising a forming element having a flat entrance end for receiving the strip, a substantially cylindrical exit end concentric with the exit path and intermediate lateral portions curving from the fiat entrance end to the cylindrical exit end to form a trough-like structure open from the entrance end for over half the length of the forming element, the forming element being bent arcuately longitudinally to produce a concave contour in the trough-like structure of the forming element, a trough-like guide inverted in the open portion of the trough-like structure of the forming element and 'bent arcuately longitudinally to produce a convex contour parallel with the concave contour of the forming element to guide the cable core and cause the cable core to exert a force against the central portion of the metallic strip advancing through the forming element to cause it to travel in the laterally and longitudinally curved path provided by the forming element, the length of the curved path followed by the central part of the strip being substantially equal to the length of the spiral paths followed by the edgs therby minimizing stretching thereof, arcuately curved elongated reinforcing bars fixed respectively to outer surfaces of the forming element and the guide to maintain the arcuate curvature thereof, and supporting brackets fixed respectively to the bars to maintain the relative parallel spaced positions of the forming element and the guide.

References Cited in the file of this patent UNITED STATES PATENTS 146,358 Qualding et al Jan. 13, 1874 449,168 Norman Mar. 31, 1891 696,865 Friel Apr. 1, 1902 2,145,867 Fentress et al. Feb. 7, 1939 2,285,263 Fitch June 2, 1942 2,306,710 Osterhorn Dec. 29, 1942 2,372,645 Barmack Apr. 3, 1945 2,373,531 'Bertalan Apr. 10, 1945 2,692,003 Nieman et al Oct. 19, 1954 

